Make CPWL_Wnd::GetProvider() a protected method.

At the present time, the sub-classes do not call this, but there is
nothing wrong from a layering perspective if they wanted to do so.

Change-Id: Ica73cc59d274f96fb43a482aa555158edea51643
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/96470
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Auto-Submit: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/fpdfsdk/pwl/cpwl_wnd.h b/fpdfsdk/pwl/cpwl_wnd.h
index 5a7a644..8dd5c5c 100644
--- a/fpdfsdk/pwl/cpwl_wnd.h
+++ b/fpdfsdk/pwl/cpwl_wnd.h
@@ -228,9 +228,6 @@
   CPWL_ScrollBar* GetVScrollBar() const;
 
   IPVT_FontMap* GetFontMap() const { return m_CreationParams.pFontMap.Get(); }
-  ProviderIface* GetProvider() const {
-    return m_CreationParams.pProvider.Get();
-  }
 
   int32_t GetTransparency();
   void SetTransparency(int32_t nTransparency);
@@ -254,6 +251,9 @@
 
   bool IsValid() const { return m_bCreated; }
   CreateParams* GetCreationParams() { return &m_CreationParams; }
+  ProviderIface* GetProvider() const {
+    return m_CreationParams.pProvider.Get();
+  }
   CFX_Timer::HandlerIface* GetTimerHandler() const {
     return m_CreationParams.pTimerHandler.Get();
   }